Measuring and indicating device



June 9, 1942. J. E. KERRIGAN 2,285,723

MEASURING AND INDICATING DEVICE Filed May 1a, 1940 2 Sheets-Sheet 1 25121 1/) v 14 r 1 I 1 11 b L f ATrolgNw June 9, 1942. J. E. KERRIGAN 2,285,723 7 MEASURING AND INDIGATING DEVICE F iled May. 18, 1940 2 Sheets-She et 2 Bl E Y I Y "I I "1,111.11" 114 z 27 i 25 22 INVENTOR. L/ase 0%/fier/z ya,?

ATTORNEYS.

Patented June 9, 1942 UNITED STATS PATENT OFFICE 3 Claims.

This invention relates in general to measuring and indicating devices, and more particularly to mechanism for accurately ascertaining the exact position of a football on the playing surface or football field, longitudinally thereof.

As is Well-known, after the ball has been put in play in the game of American football, it must be advanced longitudinally of the playing field by the team in possession of it for a distance of at least ten yards within four downs or tries. Thus it is necessary for the referee and his assistant, the head linesman, to keep as accurate as possible account of the progress of the ball. At present, it is customary for the assistants to the head linesman to employ a yardage indicator comprising a pair of rods or sticks secured at opposite ends of a ten yard chain, or the like; one stick being forced into the ground on the side line of the playing field on a transverse line with the initial position of the football, and the other stick being placed on the side line the length of the chain from the first stick in the direction of play for the offensive team. The position of the second stick thus indicates a transverse line on the field beyond which the ball must be advanced in no more than four downs by the offensive team.

It will be appreciated that it is impossible to place such yardage indicators with any degree of accuracy, especially when the football is resting adjacent the opposite side of the field, except on the rare occasions when the ball is placed directly on one of the usual transverse five yard lines. And even under such circumstances, there is no certainty of accurate results, since the yardage lines themselves vary in width and direction.

The greatest chance for error, however, either accidental or intentional, comes about when it is desired to ascertain whether or not a first down has been made, when the ball is sufiiciently close to the necessary point as to require an actual measurement directly adjacent thereto. Such measurements are made by the head linesman picking up the chain of the yardage indicator at that portion thereof which is in engagement with the center or an edge of the nearest transverse five yard line on the field. The yardage indicator is then carried out on the field, and the head linesman places that portion of the chain which he is holding in proper engagement with the said transverse yardage line in alinement with the ball longitudinally of the field. The referee then takes the stick at the forward end of the chain and straightens the chain out to its full extent to ascertain whether or not the ball has been moved the requisite distance. In addition to the usual inaccuracies of the transverse yardage lines on the field, it will be readily apparent that the chances for error in so measuring the position of the ball are manifold.

A principal object of the instant invention, therefore, is the provision of apparatus for accurately measuring and indicating the exact longitudinal position of a football on a playing field, which completely eliminates the possibility of erroneous results, regardless of the accuracy or inaccuracy of the usual transverse yardage lines provided on the playing surface.

Another important object of the invention is the inclusion in such apparatus of means movable longitudinally of the playing field for sighting the football in any position of rest thereof on the playing surface.

A further important object of the invention is the provision of means associated with such sighting means for insuring accurate parallel movement thereof relative to the side lines of the playing field, and for limiting'the line of sight to the ball in any instance to a line which is truly perpendicular to the side lines.

Another important object of the invention is the inclusion in such apparatus of means for accurately indicating the exact location of any such line of sight, longitudinally of the playing field.

A further object of the invention is the provision of apparatus for following the progress of a football on a football field'to accurately determine the distance which the ball is advanced in each successive down.

Another object of the invention is the inclusion in such apparatus of means for indicating at all times the remaining distance. necessary to advance the football inorder to make a first down.

Numerous other objects and advantages of the invention will be apparent as it is better understood from the following description, which, when taken in connection with the accompanying drawings, discloses a preferred embodiment thereof.

In the drawings,

Figure 1 is a top plan view of a football field, with parts broken away, showing a device embodying the features of the instant invention mounted in a preferred manner adjacent thereto;

Figure 2 is a front elevational view of the measuring device of Fig. 1, with parts thereof broken away;

Figure 3 is a longitudinal, vertical sectional view of the device of Fig. 2;

Figure 4 is a transverse, vertical section, taken substantially on the line 44 of Fig. 3;

Figure 5 is a front elevational view of the supplemental indicating portion of the device, with parts broken away;

Figure 6 is a transverse, vertical section taken on the line 6-6 of Fig. 5; and

Figure 7 is a detail view similar to Fig. 3 showing a modified arrangement of track and driving gear mechanism.

Referring more particularly to Fig. 1, reference numeral ll indicates in general a football field or playing surface which, as is customary, is divided longitudinally thereof by a plurality of yardage stripes I2 spaced five yards apart to define a playing surface one hundred yards long bounded at each end by a goal line l3. The playing field extends beyond each goal line [3 for a distance of ten yards to provide what is known as the end zones M. The football field II is one hundred sixty feet wide, being bounded by the usual side lines l5.

Heretofore, the position of the football on the playing field H and the progress thereof has been indicated by a suitable yardage marker comprising rods or sticks attached to the ends of a ten yard chain, or the like, placed laterally opposite the ball along one or the other of the side lines 15. The measuring and indicating device of the instant invention is indicated generally by reference numeral l3, and is adapted to be positioned any desired distance from and parallel with one of the side lines 5. The preferred embodiment thereof herein illustrated, comprises a sight and indicating unit, designated generally by reference numeral H, which is supported by, and mounted for longitudinal movement on, a track structure, indicated generally by reference numeral l8.

The track structure 58 comprises a rail or beam 19 extending the full length of the playing field l I parallel with one of the side lines I5, which rail is preferably I-shaped in cross-section, as shown in Fig. 4. The rail [9 is supported at suitable spaced intervals by post members 2! which are permanently secured or embedded in the ground at their lower ends in any desired manner. As is seen best in Fig. 4, the rail I9 is preferably attached to the posts 2! by means of bolts 22 which extend upwardly through enlarged apertures 23 provided in the lower flanges of the rail. The purpose of the enlarged apertures 23 is to permit adjustment of the rail I9 relative to the posts 2| to enable accurate positioning of the rail l9 in true parallel relationship to the side lines of the playing field II.

The upper surface of the rail I9 is provided with a longitudinally extending groove 24 (Figs. 3 and 4) within which a chain 25 is disposed. This chain 25 may be anchored in any suitable manner to the rail l9, but for the sake of extreme accuracy and in order to compensate for any expansion and contraction thereof due to changes in temperature, it is preferred that the chain be anchored at its mid-point, namely opposite the fifty yard line l2 of the playing field, to the rail l9, while being resiliently secured by means of suitable springs, or the like, to the rail 19 at its ends.

The unit I! comprises an outer casing 26, the front and rear walls of which extend downwardly beyond the end walls and terminate at their lower ends in horizontally extending flanges 21 (Fig. 4). A plurality of rollers 28 are pivotally mounted upon the flanges 21, the rollers on one of the flanges being so spaced relative to those on the other that they frictionally engage opposite sides of the central or web portion of the rail l9. A plurality of vertically disposed wheels 29 are pivotally secured in any suitable manner to the casing 26 adjacent the lower end thereof (Figs. 2, 3 and 4) so as to contact the upper surface of the rail l9 and support the unit ll thereon. As will best be seen from Fig. 4, the wheels 29 and rollers 23 permit movement of the unit l1 longitudinally of the rail is, while preventing any lateral twisting of the unit relative thereto.

Extending through the front and rear walls of the casing 25 and journaled therein in any desired manner is a shaft 3i (Figs. 2, 3 and 4), which is provided with a crank 32 rigidly secured to the forward end thereof and disposed exteriorly of the casing 26. A sprocket wheel 33 (Figs. 3 and 4) is keyed to the shaft 3i interiorly of the casing 25, and is adapted to engage the chain 25 mounted in the groove 24 of the rail l9. With this arrangement, the unit I! may be moved along the rail 19 by merely pushing the same longitudinally thereof, or by rotating the crank 32, and the longitudinal position of the unit relative to the rail will be accurately determined at all times by the sprocket wheel '33. If the chain 25 is provided with three links to the inch, and the sprocket wheel 33 with thirty-six teeth evenly spaced about its circumference, one complete rotation will be imparted to the shaft 3| for each foot of travel of the unit I! longitudinally of the rail IS.

The mechanism above described is thus adapted to position the unit I! relative to the rail l9 longitudinally thereof, and means are provided for accurately indicating the longitudinal position of the unit relative to the playing field 'II. A gear 34 (Figs. 3 and 4) is keyed to the shaft 3|, interiorly of the casing 26, which meshes with a gear 35 rotatably mounted upon a suitable stud shaft 36 secured to the front wall of the casing. A shaft 31 extends through the front and rear walls of the casing 26 and is rotatably supported thereby similarly to the shaft 3|. A gear 38 is keyed to the shaft 3'! and meshes with the gear 36. If the gears 34 and 35 are each provided with twelve teeth, and the gear 38 is provided with thirty-six teeth, it will be seen that the shaft 3'! will be given one com plete rotation for each yard of longitudinal travel of the unit I! relative to the track [9. For the purpose of indicating such movement of the unit I! to the operator thereof, a disc 39 (Figs. 2 and 4) is rigidly secured to the forward end of the shaft 31 exteriorly 0f the casing 26, the disc being divided circumferentially into three graduations representing feet, and being further divided into smaller graduations representing inches. A suitable stationary pointer 4| may be secured in any desired manner to the front wall of the casing 26 for cooperation with the disc 39.

Adjacent the gear 38, interiorly of the Casing 26, is a small gear 42 which is rigidly secured in any suitable manner to the shaft 3?. The gear 42 meshes with a similar gear 43 which is rotatably mounted upon a suitable stud shaft 44 secured to the rear wall of the casing 26. A larger gear 45 (Figs. 3 and 4) meshes with the gear 43 and is secured to a shaft 46 which extends through the front and rear walls of the casing 26 and is rotatably supported thereby similarly to the shafts 3| and 31. If each of the gears 42 and 43 areprovided with twelve teeth, and the gear '45 is provided with one hundred twenty teeth, it will be seen that the shaft 46 will be given one complete revolution for each ten rotations that are imparted to the shaft 31. Consequently, each rotation of the shaft 46 will be equivalent to a longitudinal movement of ten yards of the unit I! relative to the rail IS. The shaft 46 is therefore provided at its forward end with an indicating disc 41 (Fig. 2) which is divided circumferentially into ten equal spaces, each of which represents a longitudinal movement of one yard of the unit 11. Each of these ten spaces are further divided into three spaces, each of which in turn represents one foot of travel of the unit I1; and a stationary pointer 48, similar to the pointer 4|, is provided for cooperation with the indicating disc 41.

A gear 56 which is similar to the gear 42 is secured to the shaft 46 interiorly of the casing 26 and meshes with a similar gear 49 rotatably mounted upon a suitable stud shaft secured to the forward wall of the casing. A larger gear 52 meshes with the gear 49 and is rigidly secured to a shaft 53 extending through the front and rear walls of the casing 26 and rotatably supported thereby similarly to the shafts 3|, 31, 46. If each of the gears 56 and 49 are provided with twelve teeth and the gear 52 with one hundred twenty teeth, it will be seen that the shaft 53 will be given a complete revolution for each ten rotations imparted to the shaft 46. Thus a complete rotation of the shaft 53 will be comparable to a longitudinal movement of the unit H on the track IQ of a distance of one hundred yards, which is equal to the length of the playing field I l between the goal lines [3. An indicating disc 54 is rigidly secured to the forward end of the shaft 53 for cooperation with a stationary pointer 55 similar to the pointers 4i and 48 (Fig. 2). Since it is customary to designate the various yardage lines l2 on the playing field II in increments of ten yards, up to fifty, the center line of the field being referred to as the fifty yard line, (neither of the ten yard lines ever being referred to as the ninety yard line, for example), the indicating disc 54 is divided circumferentially into ten equal spaces which are designated in each direction away from the starting point as It), 26,

30 and 46, with the center mark being designated by the numeral 56. If the unit II, when disposed directly opposite the left hand goal line 13 of Fig. 1, has the several dials 39, 61 and 54 positioned as indicated in Fig. 2, it will be seen that longitudinal movement thereof to the right for a distance of ten yards will result in the indicating discs 39 and 47 being moved around and back to their same starting positions, while the disc 54 will have been moved to aline the graduation indicated by ID with the stationary pointer 55. Thus, continued movement of the unit I! to the right along the rail l9 will result in the numeral 56 on the disc 54 being alined with the pointer 55 when the unit reaches the mid-point of the field, and with the second one of the numerals 40 on the disc 54 being alined with the pointer 55 after the unit has been moved a total of sixty yards from its initial starting point.

In order to properly and accurately aline the unit ll with any given position of the football on the playing field, a sighting glass or telescope 56 (Figs. 2 and 4) is mounted for vertical swinging movement intermediate its ends by a trunnion support 5! which is in turn rigidly secured at its base in any suitable manner to the top of the casing 26. The telescope 56 is provided with the usual cross hairs, and is frictionally held by the trunnion bracket 51 to prevent accidental Vertical displacement thereof. The purpose of permitting vertical swinging adjustment of the telescope 56 is to enable the focusing of the same upon the football, regardless of the particular transverse position of the latter relative to the playing field. Such adjustment of the telescope 56 also compensates for differences in height of different operators of the device, the posts 2| of the preferred embodiment of the structure herein illustrated preferably being of sufficient height to bring the telescope substantially level with the height of the average mans eye above the ground.

Consequently, when the ball is placed onth field prior to being put in play on a first down, the operator moves the unit I1 longitudinally along the rail [9 until a predetermined portion of the ball, such as the nose thereof, is brought into accurate alinement with the vertical cross hair of the telescope 56. In so sighting the ball through the telescope 56, the unit I! may be pushed or pulled along the track l9, and the crank 32 may be subsequently employed to make the necessary accurate alinement of the vertical cross hair in the telescope 56 with the desired portion of the ball. The operator then checks the readings of the several indicators 29, 41 and 54, making a notation thereof, which readings represent an absolutely accurate determination of the exact position of the football longitudinally of the playing field. As play progresses and the position of the football longitudinally of the field changes, the unit I! is alined therewith at the end of each down by sighting the predetermined portion of the ball in alinement with the vertical cross hair of the telescope 56. The

dials 39, 41 and 54 will thus give an accurate indication of the progress of the ball, and as soon as the registration thereon comprises ten yards more than that noted on the first down, it will be readily apparent that a first down has been made by the offensive team. At the same time, the exact distance which it is necessary to further advance the ball in order to cover the necessar ten yards will be readily apparent after any given down.

The accuracy of the instant construction is such that the position of the ball may be positively determined within asmall fraction of an inch. Thus, there is no possibility of error, such as is present in the yardage indicators heretofore employed. If desired, after the first reading has been obtained, indicating the position of the ball on the first down, the unit I! may be advanced in the direction of play of the offensive team a distance of ten yards, where it may remain until the ball has been advanced'beyond that point, if such advancement is accomplished in not more than the required four downs. This latter method of operation of the unit, however,- is not particularly satisfactory, since it does not result in an exact determination of the distance remaining to be covered in the further advancement of the ball within the maximum number of downs.

From the above description, it will be readily apparent that the track I8 and unit I! may be disposed at any desired distance from the playing field H, so long as the track is in accurate parallelism with the side line of the field. For this reason, the instant construction will in nowise interfere with the playing of the game, since even though it may be positioned only five yards from one of the side lines, there will be no occasion for any collision therewith by any of the players. In some installations it ma b found to be desirable to mount the track structure l8 at the top of the stadium, where the latter is of such construction as to permit the location of the device at that point, while maintaining the track in parallelism with the side lines of the field. It will also be apparent that the rail l9 may be mounted within a recess or trench dug parallel with a side line of the field, so that the telescope 56 is positioned only a few inches above the surface of the playing field.

In this connection, Fig. 7 illustrates a modified construction which may be employed in lieu of the chain 25 and sprocket wheel 33. In the modified construction, reference numeral 53 represents a track or rail similar to the rail I 9 which is provided with a gear rack 59 formed integrally therewith or cut therein in any suitable manner. A gear wheel 6| is mounted upon the shaft 3| for cooperation with the rack 59 in substantially the same manner as the sprocket wheel 33 cooperates with the chain 25. It is also to be understood as coming within the scope of the instant invention that the unit l'l, minus the telescope 56, may be secured to one end of the rail 19, and the telescop 56 rigidly connected to the chain 25. With such an arrangement, movement of the telescope 56 to follow the playing field will move the chain 25 to actuate the sprocket wheel 33. Along this same line, slight additional modifications could readily be employed "to result in the mounting of the unit I! as a part of the usual score board provided at one end of the playing field, with the telescope 56 directly secured to the chain 25 or some similar mechanism, and the resulting movements of the chain being properly transmitted to the unit ll. It is also apparent that the unit I! may be employed in the manner herein illustrated and described, with the addition of a set of indicating discs similar to the discs 69, 4'! and 56 being mounted on the score board and operated in any suitable manner, such as electrically, in accordance with the position of the former.

Since it is highly desirable from a spectators standpoint, as well as from the standpoint of the players, to give a clear visual indication of the remaining yardage which it is necessary for the offensive team to make after each successive down, mechanism adapted to accomplish this function is herein illustrated in Figs. and 6. This mechanism comprises a unit indicated generally b reference numeral 62 which is enclosed within a suitable casing 63. The casing 63 is preferably rigidly secured to the casing 26 of the unit I! by means of suitable tie rods or the like 64 (Figs. 2 and 5). Rotatably secured interiorly of the casing 63 and extending between the front and rear walls thereof is a shaft 65 (Fig. 6) upon which is fixed a pulley wheel 66, which is adapted to be operated by a belt 6! (Fig. 2) driven by a pulley wheel 68 (Fig. 4) which is rigidly secured to the shaft 46. The shaft 65 will thus be rotated in unison with the shaft 46, which is given a complete rotation for each ten yards of longitudinal travel of the unit l'l.

Rigidly secured to the shaft 65 on opposite sides of the pulley 66 are a pair of gears 69 and H (Fig. 6). A second shaft 12 is rotatably mounted and extends through the front and rear walls of the casing 63 in parallel relationship with the shaft 65, the shaft 12 also being adapted for sliding movement axially thereof relative to the casing. A gear 13 is rigidly secured to the shaft 12 which is adapted to mesh with the gear 69 when the shaft is in its longitudinal position of Fig. 6. Another gear 14 is also rigidly secured to the shaft 12 which is in permanent engagement with an intermediate gear 15 supported by a suitable bracket 16, which is secured at its upper end to the shaft 12 and is slidably mounted at its lower end on the shaft 65. When the gear 13 is in mesh with the gear 69, the gears I4, 75 are disposed to one side of and out of engagement with the gear H, as shown in Fig. 6. In this position of the parts, the shaft 12 will be rotated by the shaft 65 in the opposite direction therefrom. When the shaft 12 is moved to the left f its position of Fig. 6, the gear 13 is first disengaged from the gear 69, and then the gear 15 is meshed with the gear H. The ratio of the several gears is such that when the gear 15 engages the gear H, the shaft 12 will be rotated by the shaft 65 in the same direction as the latter, and at the same speed as the gears 69, F3 rotate the shaft 12, although the latter rotation is in the opposite direction.

A large indicating disc 11 is rigidly secured to each of the outer ends of the shaft 12 exteriorly of the casing 63. Each of the discs 11 is graduated in the same manner as the disc 41 of the unit I1, and cooperates with a suitable stationary pointer 18 fixed to the casing 63. Means are provided for shifting the shaft '12 axially to cause rotation thereof in either direction. This means includes collars 19 rigidly secured to the shaft 72 in spaced relationship to each other, and a pin member 8| disposed therebetween and extending upwardly through a suitable slot provided in one end of a bell crank 82. The bell crank 82 is pivotally mounted at 83 intermediate its ends on a suitable bracket 84 secured to the back Wall of the casing 63. The other end of the bell crank 82 is also provided with a slot through which the upper end of a rod 85 extends. The lower end of the rod 85 is rigidly secured to, or formed integrally with, a horizontally disposed shaft 86 extending forwardly through, and rotatabl mounted in, the front wall of the casing 63. The forward end of the shaft 86 is provided with a crank or handle B1 rigidly secured thereto in any desired manner.

With this arrangement, swinging of the crank 81 to the left of its position in Fig. 5, or forwardly in Fig. 6, will swing the bell crank 82 about its pivot 83 to move the pin member 8| and the shaft 12 to the left in Fig. 6. This will cause disengagement of the gear 13 from the gear 69, and subsequent engagement of the gear T5 with the gear ll. Consequently, if the unit i1 is being moved to the right of its position of Fig. 2 in following the progress of the ball, the crank 81 will first be moved to its position of Fig. 5, wherein the discs 11 will be rotated in unison with and in the opposite direction from the disc 4?. The discs 11 will thus show the number of yards which it is necessary for the offensive team to gain in that particular set of downs. For example, if the ball has been advanced two yards from its original position on first down. and the indicator 4! was originally in its position of Fig. 2, the latter will now indicate two yards, the distance which the ball has been advanced, and the indicators 11 will indicate eight yards, the distance which it is necessary for the offensive team to advance the ball in order to make a first down.

When the direction of the play is opposite that above described, the operator will first move the crank 81 to the left from its position of Fig. 5. In so doing, the gear 13 will first be disengaged from the gear 89 before the gear 15 is engaged with the gear II. It is desirable to return the indicatingdiscs 11 to zero whenever the crank 81 is moved from one position to the other. This is accomplished during such period when neither the gear 13 nor the gear 15 is in mesh with their respective gears 89, H. A flexible cord or the like 88 (Fig. 6) is secured inany suitable manner at 89 at one end to the shaft I2, and at the other end to a weight 9|. As the shaft 12 is rotated in either direction, the cord 88 will be wound thereon to raise the weight 9|. In the shifting of the crank 81 from either of its positions to the other position, the weight 9| will function to return the shaft 12 to its initial position, regardless of the degree of rotation previously imparted thereto, during that period of the shifting of the crank 81 in which the gears 13' and 89, and I and H are out of engagement with each other, respectively. The discs 11 will thus function to give an accurate indication at all times of the number of yards necessary for the offensive team to advance the ball in order to make a first down. While it is apparent that this indicating unit 82 will not function to compensate for the additional yards necessary to be made by the offensive team after a penalty has been imposed thereon, such function may be readily accomplished by the addition of secondary indicator wheels to the unit 62 which will be driven thereby and will indicate any yardage in excess of ten which it is necessary for the offensive team to make for a first down.

From the above description of the preferred embodiment of the instant invention, it will be appreciated that an accurate measurement and indication of the position of the football longitudinally of the playing field will be made, regardless of the particular position of the ball laterally of the field. The outstanding advantage of the instant mechanism is that it completely eliminates all possibility of error in the measuring of the yardage in a football game. This will be true regardless of the exact location at which the mechanism may be placed, so long as proper provision is made for movement of the telescope in true parallelism to the side lines of the playing field. It will also be noted that the unit I! may be disposed at or below the surface of the playing field with the telescope 58 mounted further above the casing 28 than is disclosed in the instant drawings, such as upon a tripod, or the like, supported by the casing 28, or directly secured to the chain 25 if the latter is to be the movable element. It is also possible to provide a periscope in conjunction with the telescope 58,

the upper end of which would be disposed slightly below the eye level of the operator, if it be desired to so position the unit I! as to bring the telescope 58 only a few inches above the level of the playing field.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description, and it Will be apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention or sacrificing all of its material ad vantages, the form hereinbefore described being merely a preferred embodiment thereof.

I claim:

1. A yardage measuring and indicating device, comprising a track structure having toothlike members equally spaced longitudinally thereof, a frame mounted on said track structure for longitudinal movement, a device mounted on said frame for sighting at a fixed angle transversely of said track structure, an indicator supported by said frame, and gear means journaled in said frame and meshing with said members to operate said indicator, upon longitudinal movement of said frame, to continuously indicate the exact longitudinal position of said sighting device on said track structure.

2. A yardage measuring and indicating device, comprising a track structure having tooth-like members equally spaced longitudinally thereof, a frame mounted on said track structure for longitudinal movement, a device mounted on said frame for sighting at a fixed angle transversely of said track structure, an indicator supported by said frame, gear means journaled in said frame and meshing with said members to operate said indicator, upon longitudinal movement of said frame, to continuously indicate the exact longitudinal position of said sighting device on said track structure, and means operated by said gear means for indicating the distance said sighting device has been moved from any selected position.

3. A device of the class described, comprising a supporting structure extending in parallel relationship with and spaced exteriorly a desired distance from a side line of a football field and having tooth-like members equally spaced longitudinally thereof, means supported by said structure and movable longitudinally thereof for sighting at a fixed angle transversely across said field, gear means meshing with said tooth-like members and operable by the movement of said sighting means longitudinally of said supporting structure, and means operable by said gear means for indicating the exact and instantaneous position of said sighting means longitudinally of the football field at all times.

JOSEPH E. KERRIGAN. 

